I knew that in Ontario, floodplains are managed by the Conservation Authorities and from this list, I went on to ERCA, the Essex Region Conservation Authority. There’s no direct link on their site to flood maps, but their public GIS map application had the information I was hoping for.

For the image below, I removed all the layers except the 1:100 year floodline:

The areas around the small waterways in the area didn’t surprise me much but that large patch of blue around the neighbourhood of Riverside sure did:

These maps are a great resource. I will be investigating them further.